"How, then, does its waste — like beta-amyloid, a protein associated with Alzheimer’s disease — get cleared? What happens to all the wrappers and leftovers that litter the room after any mental workout?"

"It's [concerning sleep loss] like the difference between a snowstorm's disrupting a single day of trash pickup and a prolonged strike. No longer quite as easy to fix, and even when the strike is over, there's likely to be some stray debris floating around for quite some time yet."

"One day, scientists might be able to successfully mimic the expansion of the interstitial space that does the mental janitorial work so that we can achieve maximally efficient round-the-clock brain trash pickup."